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BUG: KCSAN: data-race in block_page_mkwrite / generic_write_end

write to 0xffff888134074a88 of 8 bytes by task 10621 on cpu 0:
 i_size_write include/linux/fs.h:907 [inline]
 generic_write_end+0x96/0x180 fs/buffer.c:2187
 ext4_da_write_end+0x448/0x510 fs/ext4/inode.c:3042
 generic_perform_write+0x261/0x400 mm/filemap.c:3776
 ext4_buffered_write_iter+0x19d/0x290 fs/ext4/file.c:268
 ext4_file_write_iter+0x227/0xda0
 call_write_iter include/linux/fs.h:2074 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x7f5/0x950 fs/read_write.c:590
 ksys_write+0xd9/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888134074a88 of 8 bytes by task 10622 on cpu 1:
 i_size_read include/linux/fs.h:885 [inline]
 block_page_mkwrite+0xb4/0x360 fs/buffer.c:2510
 ext4_page_mkwrite+0x5f2/0xcb0 fs/ext4/inode.c:6041
 do_page_mkwrite mm/memory.c:2879 [inline]
 wp_page_shared mm/memory.c:3212 [inline]
 do_wp_page+0x785/0xa80 mm/memory.c:3313
 handle_pte_fault mm/memory.c:4588 [inline]
 __handle_mm_fault mm/memory.c:4705 [inline]
 handle_mm_fault+0x975/0x1590 mm/memory.c:4803
 do_user_addr_fault+0x617/0xb90 arch/x86/mm/fault.c:1397
 handle_page_fault arch/x86/mm/fault.c:1484 [inline]
 exc_page_fault+0x91/0x290 arch/x86/mm/fault.c:1540
 asm_exc_page_fault+0x1e/0x30
 copy_user_enhanced_fast_string+0xe/0x40
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 copyout lib/iov_iter.c:155 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:226 [inline]
 __copy_page_to_iter lib/iov_iter.c:852 [inline]
 copy_page_to_iter+0x2d9/0x960 lib/iov_iter.c:880
 copy_folio_to_iter include/linux/uio.h:153 [inline]
 filemap_read+0x1126/0x1430 mm/filemap.c:2727
 generic_file_read_iter+0x72/0x320 mm/filemap.c:2822
 call_read_iter include/linux/fs.h:2068 [inline]
 do_iter_readv_writev+0x2fb/0x380 fs/read_write.c:723
 do_iter_read+0x192/0x5d0 fs/read_write.c:786
 vfs_readv fs/read_write.c:906 [inline]
 do_preadv+0x159/0x240 fs/read_write.c:998
 __do_sys_preadv fs/read_write.c:1048 [inline]
 __se_sys_preadv fs/read_write.c:1043 [inline]
 __x64_sys_preadv+0x54/0x60 fs/read_write.c:1043
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000058000 -> 0x000000000005b000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10622 Comm: syz-executor.3 Not tainted 5.17.0-rc6-syzkaller-00046-g719fce7539cd-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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